Process of making blades with soft centers.



O. A. CLARK.

PROCESS OF MAKING BLADES WITH SOFT CENTERS. APPLICATION FILED AUG. 6, 1910.

97%436o Patented Oct. 11, 1910.

.. UNITED STATES PATENT OFFIGE.

osnon A. CLARK, or NEWARK, NEW JERSEY.

PROCESS OF MAKING BLADES WITH SOFT CENTERS.

Specification of Letters Patent. Iatented Oct. 11, 1910'.

Application filed August 6, 1910.

Serial No. 575,946.

To all whom it may concern:

. Be it known that I, Osnon A. CLARK, a citizen 'of the United States, residing at Newark, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Processes of Making Blades with Soft Centers; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accomexternal support to enable them to cut, and

these blades can beleft hard and then bent, but they are so thin that they can not be ground to any extent and are usually rubbed to a cutting edge, which edge soon wears down and the keen shaving qualities of the blade are gone.

My invention enables me to utilize steel' of considerable thickness when compared to a wafer blade, and permits the steel, when it is annealed, to be bent so that when it is formed into a razor blade, even in View of its thickness, it readily conforms to any frame in which it is flexed. I have found that steel when taken in a flat ribbon or strip, as it is supplied for razor blades, and is annealed-through the center as a solid strip, cools with an unevenness in the steel and the edges do not remain straight or flat so that if the blade is laid on a flat surface one or more of its'corners will not lie on the surface and the blade is twisted. In my improved method this is overcome as I punch holes through the stock and then anneal the strip, and the perforated portion, which is usually along the line of the softening, takes up in the material betweenthe perforations the unevenness which might result from the cooling, and the blades when they are finished are just as flat as those that are not annealed.

The invention is illustrated in the accompanying drawing, in which Figure 1 is a face View of a piece of stock as used for making razor blades, and Fig. 2 is an edge view thereof. Fig. 3 is the strip shown in Fig. 1 after it has been perforated. Fig. 4 is a view of one means for softening the strip'of steel at certain points. Fig. 5 is a view of a completerazor blade, andFig. 6 is a view similar to Fig. 5, but of a different form of blade.

I take any suitable strip of steel 10 as shown in Fig. 1, which steel is of a thickness that does not permit its being readily'bent in its hardened condition, and if it is bent when it is hard it is-very liable to fracture.

The'steel'is also? thick "enough to beground to a cutting edge at one or both of its side edges. The strip is then punched with a series of perforations 11, this punching being done through the soft stock. The perforations can be of any outline and of course will depend on the frame in which the blade is to be used, and the perforations can be disposed as desired. I have formed the perforations 11 in Figs. 2 and 5 and dilferentperforati'ons 12 in Fig. 6. In the usual form of razor blade these perforations are placed alon the center line of the strip that afterwar becomes the center line of the blades.

After these perforations are put in the strip,

soft and then hardened, the strip is subjected to heat along the line of the perforations, which take up the shrinka e, and make a flat blade, the heat being so cient to anneal the stock and make it softer between the perforations, and is designed to make the material between the perforations soft and more flexible than the rest of the blade, and when more flexible, to be less liable to break.

In Fig. 4 I show one means of annealing the blades which I have used with success, this method consisting of a pair of rolls 13 which are heated by any suitable means, such as jets 14, these rolls cont-acting with the blades on their peripheries 15, which peripheries are made as wide as the strip that is to be annealed through the blades. This method anneals that part of the strip or blades only and prevents the edges of the blade from becoming annealed and the edges remain hard so that they can be formed into a good cutting edge. The annealed strip extending along the line of the perforations and extending from one perforation to the other is indicated by the line 16 in Figs. 3 and 5. The strip is out into blades along the lines 17, and I do not wish to be understood as limiting myself to blades of the particular shape shown herein, since the ends and the perforations might be constructed according to the razor 1n which the blade is to be used.

The preferred method for making the blades from the strip is to perforate the strip while the stock is soft, then harden and temper it, then of the strip, and finally out the strip into blades along the lines 17 or similar lines. It will be understood, however, that each blade can be made separately, that is, the

blades can be cut first, then perforated and then annealed by being placed in contact with the necessary heat. The perforations in the annealed strip leave enough material between the perforations and take up any unevenness that occurs in the blade while cooling, and I have found that razor blades anneal the perforated portion made according to this method remain perfectly fiat after having been annealed in the manner above described.

Having thus described my invention, what I claim is 1. The improved method of making razor blades which consists in the provision of a strip of metal, perforating the metal between its edges, and annealing a portion of the stri said annealed portion connecting the per orations of thestrip.

2. The improved method of making razor blades which consists in the provision of a strip of metal, providing the strip of metal with a series of perforations between its side edges, then annealing the strip between its side edges and in line with the perforated portion whereby the annealed part of the strip connects the perforations, and then severing the stripl into blades.

In testimony, t at I claim the foregoing, I have hereunto set my hand this 26th day of July 1910.

OSROE A. CLARK.

Witnesses: E. A. PELL,

M. A. JOHNSON. 

